Controlling ground clearance in a self-propelled agricultural product applicator

Abstract

A system, apparatus and method for detecting and controlling the height of a frame of a self-propelled agricultural product applicator above a ground surface utilize a trailing link suspension system including an angular position sensor and extensible air strut, for connecting ground engaging wheels of the applicator to the frame of the applicator. Height of the applicator above the ground surface is determined by measuring relative angular rotation of upper and lower suspension arms of the suspension system about a suspension pivot axis, using the angular position sensor. Height is controlled by regulating a flow of pressurized air to the air strut, to thereby control extension of the air strut in a manner that controls a frame to axle, ride-height, distance of the suspension system.

Description

FIELD OF THE INVENTION[0001]This invention relates generally to self-propelled agricultural product application implements, such as a high-clearance sprayer and / or spreader, and more particularly to a suspension system for such implements.BACKGROUND OF THE INVENTION[0002]Modern agricultural practices rely heavily on precise and timely applications of fertilizers, herbicides, pesticides and other chemicals. In situations where the applications must be made to standing row crops, such as corn or beans, liquid or granular materials are often applied using a high ground clearance, self-propelled applicator.[0003]In order to provide maximum ground clearance, such applicators utilize highly specialized suspension systems for connecting the ground engaging wheels of the applicator to a frame of the applicator. Typically, separate hydraulic drive motors are provided as part of the suspension, for each drive wheel, to thereby further enhance ground clearance by minimizing the encroachment of...

AI Technical Summary

Benefits of technology

The invention relates to a suspension system for connecting a ground engaging wheel to a vehicle frame using a trailing-arm suspension system. The system includes an upper suspension arm, a lower suspension arm, a load bearing suspension element, and an angular position sensor. The lower suspension arm provides support to the ground engaging wheel and allows it to rotate around a rolling axis. The method includes connecting multiple ground engaging wheels to the frame using individual suspension systems and controlling the flow of pressurized air to achieve the desired angular rotation and control the extension of the suspension systems and the height of the frame above the ground surface. The technical effect of the invention is to provide a reliable and efficient connection between the ground engaging wheel and the frame, allowing for controlled movement and adjustable height of the applicator frame above the ground surface.

Problems solved by technology

While these components have generally worked well in the specialized suspension systems of high ground clearance, self-propelled applicators, they are not ideal and further improvement is desirable.

One problem with prior high clearance applicator suspension systems, is that the ground clearance tends to vary depending upon how heavily the applicator is loaded.

Having ground clearance vary is undesirable for at least two reasons.

First, the effectiveness of the product being applied is highly dependent upon precise application.

As ground clearance changes, spray or granular spreading patterns may be adversely affected, requiring continual compensating adjustments to be made by an operator of the applicator, in order to maintain optimal product application.

Second, ride quality and handling characteristics of the applicator are typically affected by ground clearance, and the state of extension of the compression springs.

This results in compromising suspension performance in other operating modes that are typically necessary in practical utilization of the applicator.

Differences in handling characteristics inherent in spring based suspension systems, from loaded to unloaded states of the applicator, may make such on-road transit more difficult.

This can present additional problems for high ground clearance applicators, in that the overall combined height of the applicator and the bed of the trailer or vehicle carrying the applicator may exceed applicable limits for transport on public roads.

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